Bikram Sambat (abbreviated "B.S.") is the official calendar of Nepal. It is a lunar calendar based on ancient Hindu tradition (see Hindu calendar and Vedic time keeping). The Bikram Sambat calendar is 56.7 years ahead of the solar Gregorian calendar currently in worldwide use. Therefore, the year 2000 CE was equivalent to the years 2056-2057 BS.

The Bikram Sambat calendar starts with the first day of month of Baisakh (the Chaitra Purnima ) which is in mid-April in the Gregorian calendar.

The Nepali New Year is one of the many festivals of Nepal, marked by parties, family gatherings, the exchange of good wishes and participation in rituals to ensure good fortune in the coming year.

In addition to Nepal, elements of the Bikram Sambat calendar are also recognized in north India and Bengal state. In Bangladesh, the new year is celebrated as "Poila Baisakh," a national holiday.